This invention relates to improvements in manual sprayer devices comprising a body fixable to a container containing the liquid to be sprayed, a cylinder in said body, a piston movable within said cylinder, and a trigger-type operating lever which is rotatably mounted in said body and connected to said piston in such a manner as to move it in the two directions and on which there act elastic return means which react against the body and are out of contact with the liquid to be sprayed.
A sprayer device of this type is known for example from U.S. Pat. No. 4,153,203 (TADA). In this known device the structure of the trigger lever is particularly complicated and the piston also has a certain constructional complexity. In this respect, the trigger lever upperly comprises two outwardly projecting lugs for its hinging to the body (this requiring the presence of counteracting means between the two lugs to prevent their accidental escape from the body seats in which they are held), two external projections in a middle position for connecting the return spring, an inner shaped thrust surface and grooves or seats for connecting the piston to enable movement to be transmitted to it in the two directions. The piston itself is formed from two parts, one of which comprises transverse pins for connecting the trigger lever and a tang for deforming a gasket.